One early hydrotherapy system consisted of a drive motor mounted on the exterior of a tub and connected to a pump within the tub by means of a drive belt extending over the edge of the tub. U.S. Pat. No. 2,417,499 proposes a similar arrangement in which a motor is mounted above the tub on a bracket suspended on one wall of the tub and connected via a vertical shaft to an impeller located in the interior of the tub. These devices get in the way of the user, present a poor appearance, require a great deal of space both inside and outside the tub, are complicated in construction and include a number of parts that are subject to wear and possible malfunction and have other disadvantages. In recent years the hydrotherapy industry has almost universally adopted an arrangement in which a single pump is connected by means of rigid polyvinylchloride pipe and pipe fittings to a plurality of hydrotherapy jets located at various points around the periphery of the tub. These installations are not only expensive because of the plumbing and assembly required but in addition there are substantial frictional .losses within the pipe and fittings which rob power and reduce efficiency. Moreover, the entire plumbing system must be leak tested before the unit leaves the factory. Once in the home, access doors are required around the tub for waste and overflow, for servicing the pump, etc., and the plumbing. Furthermore, the pump and motor require a fairly large space under the skirt of the tub which is a major disadvantage for installations in homes which often have limited room. In addition, because the water circulates through exteriorally located pipes, it cools off more quickly thus wasting heat. Since a single suction opening with a high velocity inlet area is used for a number of jets, there have also been problems with parts of the body or hair being drawn against or into a suction fitting (see U.S. Pat. No. 4,596,656 by Higginbotham and Jaworski). This can be uncomfortable or even dangerous.
In view of these and other deficiencies of the prior art it is one object of the present invention to provide an improved hydrotherapy jet and pump assembly which will overcome the aforesaid deficiencies, which will not be in the way of the user, which is attractive in appearance and in which there is minimal water circulation outside the confines of the hot tub, spa, bathtub, whirlpool or pool.
A further object is to provide an improved hydrotherapy pump and jet assembly which furnishes substantially the same hydrotherapy effect for the user of the tub as the units in current use but requires no external plumbing, allows servicing from inside the tub and at the same time keeps the pump and pump motor out of the way of the user and hidden from view. A further object is to provide a system for automatically reducing the harmful or uncomfortable suction that results when a portion of the body comes close to the water suction inlet, increasing pumping efficiency, reducing heat loss and assisting in heating the water being pumped.
These and other more detailed and specific objects of the present invention will be described in more detail in the accompanying figures and specification which illustrate a few preferred forms of the invention by way of example.